Research and Application of"Soft"Devices for Realizing Servo Amplification

This article analyzes and discusses the working principle and problems encountered by various servo amplification devices used in the on-site continuous adjustment system,analyzes and discusses the application of the servo mechanism,and analyzes the mechanism of the servo device's implementation of the"positioning"func-tion on the control device.Intended to guide the continuous adjustment process in controlling the function/accuracy of actuator equipment and application debugging,ensuring the safe and stable operation of production equipment and facilities.

Alternative polyadenylation events in epithelial cells sense endometritis progression in dairy cows

Endometritis(inflammation of the endometrial lining) is one of the most devastating reproductive diseases in dairy cattle, resulting in substantial production loss and causing more than $650 million in lost revenue annually in the USA.We hypothesize that alternative polyadenylation(APA) sites serve as decisive sensors for endometrium health and disease in dairy cows. Endometrial cells collected from 18 cows with purulent vaginal discharge scored 0 to 2 were used for APA profiling with our whole transcriptome termini site sequencing(WTTS-seq) method. Overall, pathogens trigger hosts to use more differentially expressed APA(DE-APA), more intronic DE-APA, more DE-APA sites per gene and more DE-genes associated with inflammation. Host CD59 molecule(CD59), Fc fragment of IgG receptor IIa(FCGR2A), lymphocyte antigen 75(LY75) and plasminogen(PLG) may serve as initial contacts or combats with pathogens on cell surface, followed by activation of nuclear receptor subfamily 1 group H member 4(NR1H4) to regulate AXL receptor tyrosine kinase(AXL), FGR proto-oncogene, Src family tyrosine kinase(FGR), HCK protooncogene, Src family tyrosine kinase(HCK) and integrin subunit beta 2(ITGB2) for anti-inflammation. This study is the first to show significance of cilium pathways in endometrium health and animal reproduction. MIR21 and MIR30A would be perfect antagonistic biomarkers for diagnosis of either inflammation or anti-inflammation. These novel findings will set precedent for future genomic studies to aid the dairy industry develop new strategies to reduce endometritis incidence and improve fertility.

Diagnostic and classification value of immune-related lncRNAs in dilated cardiomyopathy

Background:Various physiological mechanisms are linked to dilated cardiomyopathy(DCM)development,including oxidative stress,immune irregularities,inflammation,fibrosis,and genetic changes.However,precise molecular drivers of DCM,especially regarding abnormal immune responses,remain unclear.This study investigates immune-related long non-coding RNAs(lncRNAs)in DCM’s diagnostic and therapeutic potential.Methods:GSE141910,GSE135055,and GSE165303 datasets were acquired from the GEO database.LASSO,SVM-RFE,and random forest algorithms identified DCM-associated immune-related lncRNAs.Diagnostic capabilities were assessed by Nomogram and receiver operating characteristic(ROC)curves.Multivariate linear regression explored lncRNA correlations with ejection fraction.Single-sample gene set enrichment analysis(ssGSEA)gauged immune cell infiltration/functions.Functional enrichment analyses were performed using Gene set variation analysis(GSVA),gene ontology(GO),and the Kyoto Encyclopedia of Genes and Genomes(KEGG).Consensus clustering categorized DCM cases.Results:Ten immune-related lncRNAs emerged:C10orf71-AS1,FHAD1-AS1,SCIRT,FNDC1-AS1,MELTFAS1,LOC101928834,GDNF-AS1,DCXR-DT,C3orf36,and LOC107985323.These lncRNAs,tied to immunomodulation,showed promising DCM diagnostic accuracy.Adjusted for confounders,they independently correlated with ejection fraction.Using lncRNA expression,DCM patients were grouped into subtypes.Subtype C1 displayed a higher level of immune cell infiltration and immune checkpoint expression compared to subtype C2,emphasizing the variations in the immune microenvironment.Conclusion:This study identifies ten immune-related lncRNAs for further exploration in DCM diagnosis and subtyping.Based on expression patterns,we propose two potential DCM subtypes.Notably,findings are preliminary and hypothesis-generating,demanding validation and further investigation.This research provides insights into DCM diagnosis and classification.

污染环境下具有脉冲输入的随机捕食-食饵模型的动力学研究

该文研究了污染环境下具有脉冲输入的随机捕食-食饵模型,证明了系统的全局正解的存在唯一性,均值有界性,给出了系统边界周期解以概率1全局吸引的存在条件,并得到了种群灭绝与持续生存的阈值.最后用数值模拟进一步验证了理论结果的正确性.

Effects of wave-current interaction on the waves, cold-water mass and transport of diluted water in the Beibu Gulf

Wave-current interaction and its effects on the hydrodynamic environment in the Beibu Gulf(BG) have been investigated via employing the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST) modeling system. The model could simulate reasonable hydrodynamics in the BG when validated by various observations.Vigorous tidal currents refract the waves efficiently and make the seas off the west coast of Hainan Island be the hot spot where currents modulate the significant wave height dramatically. During summer, wave-enhanced bottom stress could weaken the near-shore component of the gulf-scale cyclonic-circulation in the BG remarkably, inducing two major corresponding adjustments: Model results reveal that the deep-layer cold water from the southern BG makes critical contribution to maintaining the cold-water mass in the northern BG Basin.However, the weakened background circulation leads to less cold water transported from the southern gulf to the northern gulf, which finally triggers a 0.2℃ warming in the cold-water mass area;In the top areas of the BG, the suppressed background circulation reduces the transport of the diluted water to the central gulf. Therefore, more freshwater could be trapped locally, which then triggers lower sea surface salinity(SSS) in the near-field and higher SSS in the far-field.

Unusual coastal ocean cooling in the northern South China Sea by a katabatic cold jet associated with Typhoon Mujigea(2015)

This study deals with a unusual cooling event after Typhoon Mujigea passed over the northern South China Sea(SCS) in October 2015. We analyze the satellite sea surface temperature(SST) time series from October 3 to 18,2015 and find that the cooling process in the coastal ocean had two different stages. The first stage occurred immediately after typhoon passage on October 3, and reached a maximum SST drop of –2℃ on October 7 as the usual cold wake after typhoon. The second stage or the unusual extended cooling event occurred after 7d of the typhoon passage, and lasted for 5d from October 10 to 15. The maximum SST cooling was –4℃ and occurred after 12d of typhoon passage. The mechanism analysis results indicate that after landing and moving northwestward to the Yunnan-Guizhou Plateau(YGP), Typhoon Mujigea(2015) met the westerly wind front on October 5. The lowpressure and positive-vorticity disturbances to the front triggered meridional air flow and low-pressure trough,thus induced a katabatic cold jet downward from the Qinghai-Tibet Plateau(QTP) passing through the YGP to the northwestern SCS. The second cooling reached the maximum SST drop 4d later after the maximum air temperature drop of –9℃ on October 11. The simultaneous air temperature and SST observations at three coastal stations reveal that it is this katabatic cold jet intrusion to lead the unusual SST cooling event.

Risk factors for sepsis-associated encephalopathy

Sepsis-associated encephalopathy （SAE） is a diffuse and acute cerebral dysfunction caused by sepsis. Many sepsis patients exhibit acute deterioration in mental status during the early stage of disease, and central nervous system dysfunction has been shown to increase patient mortality. The present study selected 284 sepsis patients who were admitted to the Intensive Care Unit of Beijing Friendship Hospital, Capital Medical University, from January to December 2009. The patients were assigned to SAE and non-SAE patient groups according to SAE occurrence. SAE incidence was 37.68%, and mortality was significantly greater in SAE patients compared with non-SAE patients （41.12% vs. 17.51%, P 〈 0.01）. Univariate analysis and multivariate logistic regression analysis indicated lower arterial partial pressure of oxygen and greater alanine aminotransferase and Acute Physiology and Chronic Health Evaluation II scores in the SAE group compared with the non-SAE group. Arterial partial pressure of oxygen, alanine aminotransferase, and Acute Physiology and Chronic Health Evaluation II scores were determined to be potential risk factors for SAE.

Infl uence of sequential tropical cyclones on phytoplankton blooms in the northwestern South China Sea

Upper ocean responses to the passage of sequential tropical cyclones over the northwestern South China Sea(SCS)in 2011 were investigated using satellite remote sensing data,Argo reanalysis data,and an array of mooring data.We found that the sea surface low temperature region lasted for more than 38 days and two phytoplankton blooms occurred after the passage of sequential tropical cyclones.The upper ocean cooling reached 2–5°C with a right-side bias was observed along the typhoon track to about 200 km.The maintenance of low temperature region and the two phytoplankton blooms were mainly driven by upwelling and near-inertial turbulence mixing induced by the sequential tropical cyclones.The fi rst phytoplankton bloom appeared on the 7 th day after the passage of the three tropical cyclones,and the chlorophyll-a(chl-a)concentration increased by 226%,which may be mainly driven by typhoons induced upwelling.The second phytoplankton bloom occurred on the 30 th day,the chl-a concentration increased by 290%.Further analysis suggested that only the typhoons with similar characteristics as Nesat and Nalgae can induce strong near-inertial oscillation(NIO).Strong turbulent mixing associated with the near-inertial baroclinic shear instability lasted for 26 days.The measured mean eddy diff usivity in the upper ocean was above 10-4 m 2/s after typhoon Nesat.Enhancement of the turbulent mixing in the upper ocean helped to transport nutrient-rich cold waters from the deep layer to the euphotic layer,and is a major mechanism for the long-term maintenance of low temperature region as well as the second phytoplankton bloom.

Upwelling off the west coast of Hainan Island: sensitivity to wave-mixing

The coupled ocean atmosphere wave sediment transport(COAWST)modeling system is employed to investigate the role of wave-mixing playing in the upwelling off the west coast of Hainan Island(WHU).Waves,tides and sea surface temperature(SST)are reproduced reasonably well by the model when validated by observations.Model results suggest the WHU is tidally driven.Further investigations indicate that inclusion of wave-mixing promotes the intensity of the WHU,making the simulated SST become more consistent with remote-sensed ones.Dynamically,wave-mixing facilitates the“outcrop”of more upwelled cold water,triggering stronger WHU and leading to a three-dimensional dynamical adjustment.From the perspective of time,wave-mixing contributes to establishing an earlier tidal mixing front strong enough to generate WHU and that is,WHU may occur earlier when taking wave-mixing into consideration.

Effects of Short-Term Mechanical Stretch on the Proliferation and Osteogenic Differentiation of Mesenchymal Stem Cell and TRPC1 Expression

Objective Mechanical stretch regulates mesenchymal stem cell(MSC)function,which much more emphasis has been placed its prolonged effect on lineage differentiation,especially osteogenic differentiation.In contrast,there are few reports about its short term effect on MSC proliferation.In the present study,effects of short-term mechanical stretch on the proliferation and osteogenic differentiation of mesenchymal stem cell proliferation were investigated.In addition,the stretchinfluenced expression of transient receptor potential cation channel,subfamily C,member 1(TRPC1)was also investigated due to its mechanosensitivity and positive correlation with MSC proliferation.Methods MSCs,harvested from rat bone marrow,were seeded on collagen l-coated silicone chamber and exposed to mechanical stretch with various magnitude(0%,5%,10%and 15%)or various duration(2 h,6 h,12 h and 24 h).Cell proliferation was examined by cell counting kit-8(CCK-8)assay and cell cycle analysis.The gene and protein expression of two makers for osteogenic differentiation,collagen I and Cbfα1,and TRPC1 were determined by RT-PCR and western blotting,respectively.BMSC were harvested,and total RNA was isolated with Trizol reagent.A 2μg portion of total RNA was synthesized to cDNA according to the manufacturer s instructions.cDNA was used as a template for each PCR amplification.BMSC were solubilized in RIPA lysis buffer on ice for 30 min.Phenylmethane sulfonyl fluoride(PMSF)was added to avoid proteolysis.Equal portions of the cell lysates were separated on 10%sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)and transferred to polyvinylidene fluoride(PVDF)membranes.The membranes were incubated with primary antibodies to TRPC1 and GAPDH at4℃overnight to identify the specific proteins.The PVDF membranes were washed with TBST three times and incubated with a horseradish peroxidase(HRP)-conjugated secondary antibody.Immunoreactive bands were visualized using an enhanced chemiluminescent(ECL)system.Results The OD value for the three stretch cases(5%-15%)was increased^1.4-fold compared with that for control(0%).There is no significantly difference among the three stretch cases.The percentage of cells for three stretch cases were more in the S phase but less in the G0/G1 phase compared to those for control.The cell cycle distribution still had no significant difference among the three stretch cases.In addition,the stretch application for 24 h didn’t affect the gene or protein level for collagen I and Cbfα1 compared with those of control.Application of 10%stretch for 2 h didn’t affect TRPC1 gene or protein expression,but that application for 6-24 h significantly up-regulated TRPCl gene and protein level.That increase exhibited a stretch duration-independent manner.Conclusions Short-term mechanical stretch promoted MSC proliferation in a magnitude-independent manner,whereas had no effect on its oesteogenic differentiation.Paralleled to which,TRPC1 was up-regulated by stretch,implying that TRPCl may be implicated in that proliferation courses.Future work is still needed to confirm whether TRPC1 participates in that stretch-induced MSC proliferation using RPC1 blockade or knockout.

IKCa Channel-Mediated Ca2+ Entry and ERK1/2 Activation: Implication in Stiff Substrate-Induced Vascular Smooth Muscle Cell Proliferation

Objective:Arterial stiffening occurs in the progression of natural aging and cardiovascular diseases.Vascular smooth muscle cells(VSMCs),the major components of vascular walls,which largely contribute to the pathophysiological states of blood vessels,are influenced by environmental cues of blood vessels reciprocally as well.Consistently,the increased proliferation of VSMCs has been reported to be observed in stiffening blood vessel and on rigid substrates,the underlying mechanism of which remains not yet fully clarified.Our previous work has demonstrated that Ca2+-activated K+(IKCa)channel participates in the stiff substrate-induced vascular smooth muscle cell(VSMC)proliferation.In the present work,from the standpoint of calcium entry and extracellular regulated protein kinases 1 and 2(ERK 1/2)activation,we further investigated the underlying mechanisms by which IKCa channels functions in the process mentioned above.Methods Soft(0.21 MPa)and stiff(1.72 MPa)PDMS substrates where VSMCs were seeded after coated with fibronectin(FN),were fabricated through the blending of sylgard 184 gel and sylgard 527 gel.After that,intracellular calcium level of VSMCs was compared with or without the treatment of IKCa specific blocker,TRAM-34,using a calcium-sensitive dye,fluo 4-AM.1mM Ethylene glycol-bis(2-aminoethyl ether)-N,N,N’,N’-tetraacetic acid(EGTA)was added into the culture media for the removal of the extracellular calcium ions as well as cell counting kit-8(CCK-8)assay was applied,which is to explore the role that calcium ion entry played in proliferation process.The activation level of ERK 1/2 was described by the expression level of phospho-ERK 1/2 using western blotting with or without TRAM-34 treatment.The role of the activation of ERK1/2 in VSMC proliferation was examined by CCK-8 assay with or without the treatment of PD98095,an ERK1/2 inhibitor.Results Compared with soft substrate,stiff substrate caused an increase of intracellular calcium level,which was attenuated by IKCa blockade.In addition,compared with soft substrate,stiff substrate also caused an activation of ERK1/2,which was significantly suppressed by IKCa blockade.Furthermore,extracellular calcium ion reduction by adding EGTA significantly inhibited the stiff substrate-induced VSMC proliferation,which whereas had no effect on VSMC proliferation on soft substrate.Finally,ERK1/2 inhibition had similar inhibitory effect on stiff substrate-induced proliferation.Conclusions Stiff substrate causes an IKCa channel-mediated calcium entry and ERK1/2 activation,both of which play important roles in stiff substrate-induced VSMC proliferation.Combined the previous results that IKCa channel participated in stiff substrate-induced VSMC proliferation,our present work suggests that IKCa channel functioned in the proliferation process through mediating calcium entry and subsequent ERK1/2 activations.These findings provide a new insight into how substrate stiffness regulates VSMC proliferation,and additional considerations for vascular tissue engineering and vascular disease treatment.

LAND RESOURCES SURVEY BY REMOTE SENSING AND ANALYSIS OF LAND CARRYING CAPACITY FOR POPULATION IN TUMEN RIVER REGION

The Tumen river region including Yanji,Tumen, Longjing and Hunchun cities is situated in the east part of Jilin Province.The region is an important economic exploitation area in the province. The total area is 10, 228. 86 km2.There are superior geographical location, rich natural rare, various gemorphological types and less farmaland in the region. The remote sensing technique is adopted in the survey of present landuse. The newest Landsat and CCT data are selected in the survey. Comparing the data obtained from remote sensing survey with the data from land detail investigation we can are that the paddy-field, garden for planting fruits, residential area and factory and mine, traffic land have increased in different extents, especially, the residential area is increased rapidly, but the forest land, grazing land have decreased. The unused land has been used. Land productive potentiality system is a multi-hierarchic comprehensive-complex system of natural economy.Its core is photosynthesis of green vegetation, which is affected by factors such as radiation,temperature, rainfall, soil fertility and management level. According to calculation of productive potentiality, the analysis of carrying capacity for population has ho done and the conclusion is drawn. After 2000,the population growth in the region will be reStricted by lack of are of farmland resources and level of grain production. Existing land and its reserve are can not carry a population more than 150×104.It is estmeted that the grain only depends on transportstion outside to meet the needs of population growth and social development after 2000.

Distribution and Oceanic Dynamic Mechism of Precipitation Induced by Typhoon Lekima

Air-sea interaction usually affects the distribution of precipitation during typhoon period, but whether typhoon precipitation distribution is affected by ocean eddies is still unclear. In this study, based on a multi-source satellite database, reanalysis data and in-situ data were used to study the precipitation characteristics of Typhoon Lekima (2019) as well as its physical causes. The results showed that the precipitation of Lekima presents an asymmetric structure, exhibiting heavier precipitation on the left side of the typhoon path before 7 August, and with the typhoon strengthened, precipitation was evenly distributed around the typhoon center. The typhoon cloud system, characteristics of the typhoon, and ocean factors could be responsible for the asymmetric structure of precipitation during the typhoon period. The change in the typhoon cloud system during the typhoon influenced the distribution of precipitation. And there have been some oceanic processes that influenced the distribution of precipitation. Anticyclonic eddies and thick mixing level depths (MLDs) play important roles in typhoon precipitation. The anticyclonic eddies with thick MLD exist to reduce the mixing of the upper ocean to maintain the SST. Therefore, the SST and air-sea exchange can be sustained to influence typhoon precipitation. This study provides a new understanding of the impact of ocean processes on typhoon precipitation distribution.

Er-modified MnO_(x) for selective catalytic reduction of NO_(x) with NH_(3) at low temperature:Promoting effect of erbium on catalytic performance

Various Er modified MnO_(x) catalysts were synthesized using co-precipitation approach and tested in the selective catalytic reduction of NO_(x) by ammonia(NH_(3)-SCR).Catalysts were analyzed with various characterization techniques,and it is found that the doping of Er can enormously enhance the catalytic performance of MnO_(x)catalyst.MnEr_(0.1)demonstrates advantageous catalytic performance in the NH_(3)-SCR reaction owing to rich surface acidic sites,high surface content of Mn^(4+),superior redox capacity,and enhanced surface-adsorbed oxygen.From diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis,it is suggested that the MnEr0.1catalyst follows mainly Eley-Rideal mechanism while MnO_(x) is dominated by Langmuir-Hinshelwood mechanism.

Tetra-color superresolution microscopy based on excitation spectral demixing

Multicolor imaging allows protein colocalizations and organelle interactions to be studied in biological research,which is especially important for single-molecule localization microscopy(SMLM).Here,we propose a multicolor method called excitation-resolved stochastic optical reconstruction microscopy(ExR-STORM).The method,which is based on the excitation spectrum of fluorescent dyes,successfully separated four spectrally very close far-red organic fluorophores utilizing three excitation lasers with cross-talk of less than 3%.Dyes that are only 5 nm apart in the emission spectrum were resolved,resulting in negligible chromatic aberrations.This method was extended to three-dimensional(3D)imaging by combining the astigmatic method,providing a powerful tool for resolving 3D morphologies at the nanoscale.

呼伦贝尔农垦集团草畜平衡状况与粮经饲配置模式

加快生态草牧业建设以提升草原生态承载力、促进草畜动态平衡,是实现农牧场畜牧业增产和牧区可持续发展的重要举措.本文以呼伦贝尔农垦集团24个农牧场为研究区,基于MODIS,Landsat TM/OLI和高分2号等遥感数据和农牧场草牧业年度报表数据,应用遥感解译和草地净初级生产力遥感估算模型,获取了农垦集团24个农牧场草地分布现状和退化状况,测算了各农牧场草地净初级生产力,评价了草地生态承载力和超载状况,进而提出了农牧场生态草牧业建设的粮经饲配置模式.结果表明:呼伦贝尔农垦集团24个农牧场中草地总面积的66.16%出现不同程度的退化,主要表现为草地植被生产力和盖度下降,由草原开垦等导致草地破碎化面积约占草地总面积的1.55%.遥感估算的呼伦贝尔农垦集团24个农牧场平年产草总量约为34.07万t,欠年(2001年)产草总量为27.43万t,丰年(2013年)产草总量为48.89万t.2015年农垦集团24个农牧场实际载畜量为164.19万个羊单位,理论载畜量为86.83万个羊单位,在不考虑青贮草和外购饲草料的情况下,超载率为89%,饲草缺口42.35万t.农垦集团24个农牧场现有耕地面积为3.95×103 km2,基于生态草牧业建设的理念,将其中10%的耕地开展人工草地种植,理论上相当于5.86×103 km2天然草地的产草量,完全可满足整个农垦集团牲畜饲草料需求.推行"粮、经、饲‘三元结构’、草田轮作"的生产模式,适度利用现有耕地开展粮改饲和种养结合模式,提高草地产量、有助于维护草畜平衡,遏制草地退化趋势,提高草原牧区草牧业可持续发展和生态保护能力.

CRISPR/Cas基因组编辑技术在乳酸菌中的应用及研究展望

乳酸菌是一类重要的食品工业微生物,目前对其功能基因鉴定和挖掘优良功能基因主要依赖于传统的基因同源重组技术,该技术尽管有较高的可靠性,但是存在操作繁琐、效率低下等不足,严重制约了乳酸菌优良菌株的遗传选育。CRISPR/Cas基因编辑技术极大提升了对多物种基因组的编辑效率,这为乳酸菌功能基因的快速鉴定及遗传改良提供了可能,但是现有的CRISPR/Cas基因编辑技术在乳酸菌的应用还存在诸多限制。本文综述了CRISPR/Cas基因编辑技术在乳酸菌基因组上的应用现状及亟待解决的问题,并展望了乳酸菌基因组编辑技术的未来发展趋势,为乳酸菌功能基因鉴定及遗传改良提供参考。

Aboveground biomass and its spatial distribution pattern of herbaceous marsh vegetation in China

Herbaceous marsh is the most widely distributed type of marsh wetland ecosystem,and has important ecological functions such as water conservation,climate regulation,carbon storage and fixation,and sheltering rare species.The carbon sequestration function of herbaceous marsh plays a key role in slowing climate warming and maintaining regional environmental stability.Vegetation biomass is an important index reflecting the carbon sequestration capacity of wetlands.Investigating the biomass of marsh vegetation can provide a scientific basis for estimating the carbon storage and carbon sequestration capacity of marshes.Based on field survey data of aboveground biomass of herbaceous marsh vegetation and the distribution data set of marsh in China,we analyzed the aboveground biomass and its spatial distribution pattern of herbaceous marsh on a national scale for the first time.The results showed that in China the total area of herbaceous marsh was 9.7×10^(4) km^(2),the average density of aboveground biomass of herbaceous marsh vegetation was 227.5±23.0 g C m-2(95%confidence interval,the same below),and the total aboveground biomass was 22.2±2.2 Tg C(1 Tg=1012 g).The aboveground biomass density of herbaceous marsh vegetation is generally low in Northeast China and the Tibetan Plateau,and high in central North China and coastal regions in China.In different marsh distribution regions of China,the average biomass density of herbaceous marsh vegetation from small to large was as follows:temperate humid and semi-humid marsh region(182.3±49.3 g C m^(-2))<Tibetan Plateau marsh region(243.9±26.6 g C m-2)<temperate arid and semi-arid marsh region(300.5±73.2 g C m-2)<subtropical humid marsh region(348.4±59.0 g C m-2)<coastal marsh region(675.4±73.8 g C m-2). Due to the different area of herbaceous marsh, the total aboveground biomass of herbaceous marsh vegetation in different marsh distribution regions was the largest in the temperate humid and semi-humid marsh region(9.6±2.6 Tg C), and was the smallest in the coastal marsh region(1.1±0.1 Tg C). The spatial distribution of aboveground biomass of herbaceous marsh vegetation in China has obvious non-zonality characteristics, but also presents certain zonality in some regions. The aboveground biomass of herbaceous marsh vegetation in the Tibetan Plateau decreased with the increase of altitude. With the aggravation of drought, the aboveground biomass of herbaceous marsh vegetation in temperate humid and semi-humid regions and temperate arid and semi-arid regions decreased first and then did not obviously change. The aboveground biomass of herbaceous marsh vegetation in temperate humid and semi-humid regions was relatively larger in the regions with higher average annual temperature. The results can provide scientific basis for accurately evaluating the adjustment action of wetland ecosystems on climate, and provide decision support for adaptive management of wetland ecosystems.

Improved Algorithms for Removing Isolated Non-Meteorological Echoes and Ground Clutters in CINRAD

Using China New Generation Weather Radar （CINRAD） level-Ⅱ data, the original algorithms for removing isol-ated non-meteorological echoes and ground clutters in radar data, which have been applied to Weather Surveillance Radar-1988 Doppler （WSR-88D） in the USA and Severe Weather Automatic Nowcast （SWAN） system in China, are modified and improved. To remove isolated non-meteorological echoes, the new algorithm introduces a constraint parameter （Po） to distinguish whether a window of 5 x 5 points is isolated as external echoes. A statistical analysis of 150 radar scans （5 cases, with each case comprising 30 scans） under three different echo types （small-scale convec-tion, typhoon, and large-scale synoptic system） shows that the constraint parameter Po ≤ 0.167 is suitable for remov- ing isolated non-meteorological echoes while preserving the edge of meteorological echoes. A new parameter, NDZ, which promotes the ability of the algorithm to identify the ground clutters appearing at two adjacent elevation angles, is constructed based on the vertical continuity of reflectivity. These improved algorithms are tested for four cases （three cases of isolated non-meteorological echoes and one case of ground clutters）. Based on the statistics of 232 volume scans of radar data （on a temporal resolution of 1 h） measured at Nanchang station from 0000 UTC 5 to 1600 UTC 14 March 2015, it is found that the improved algorithms not only eliminate most （over 95% under clear-sky conditions） of the isolated non-meteorological echoes and ground clutters （including those appearing at two adjacent elevation angles）, but also well preserve the structure of meteorological echoes （storms）.

Analysis of a Convective Storm Crossing Poyang Lake in China

A convective storm crossing Poyang Lake(PL)in China during 1200-1600 UTC on 13 May 2015 is examined.The results show that this storm occurs ahead of a 500-hPa trough with weak low-level temperature advection and a convectively stable layer between 925 and 850 hPa,and the tail of the storm is enhanced when its spearhead sweeps over PL after the sunset.Due to the heating and moistening of PL,the convectively stable layer over PL is destabilized;and instead,a deep(below 700 hPa)convectively unstable layer is organized.Moreover,both the radiative cooling and the storm-induced cooling result in a rapid air(near-surface)and land temperature decrease in the surrounding areas.Thus,a large lake-land temperature difference(about 6℃)occurs,which is conducive to generating land-lake breeze and enhancing the convergence of the low-level wind.Finally,the PL-induced deep convectively unstable layer and the enhanced low-level convergence jointly strengthen the crossing storm.To further confirm this,two simulations(with or without PL)are conducted with the Weather Research and Forecast(WRF)model.The simulation with PL successfully reproduces the evolution of the storm crossing PL,while the simulation without PL fails.In the simulation with PL,a highμse tongue at 850 hPa associated with the storm moves eastward and downward,and merges with the PL-induced lake boundary layer,forming a deep convectively unstable layer under 700 hPa.However,in the simulation without PL,the stable layer constantly maintains under 900 hPa.In addition,the 900-hPa wind difference between the simulations with and without PL shows a land-lake breeze circulation that strengths the convergence of the low-level wind.